DISEASES OF THE LATERAL CARTILAGES 339 
Should the mouth of a fistula become occluded with the 
granulations filling it, and the discharge prevented from 
escaping, it soon happens that we have close to the fistula 
that has closed a tender fluctuating swelling. This points 
and breaks, and pus is again discharged from another 
opening. In this manner is accounted for the multiplicity 
of scars and fistulas seen on the swelling of an old- 
standing quittor. 
The continued inflammation thus kept in existence has 
the effect of rendering the skin and subcutaneous tissues 
in the neighbourhood greatly thickened and indurated. 
This in time leads to a tumour-like enlargement, and 
causes the structures of the coronet to greatly overhang 
the hoof. At the same time the constant inflammation has 
made its stimulant effects noted in a great increase in the 
growth of the horn of the wall. 
Although more abundant, however, the quality of the 
horn is deteriorated. The perioplic ring has become 
obliterated, and the varnish-like appearance of the healthy 
wall destroyed. Cracks and fissures in its surface are 
numerous, and sometimes deep enough to lead to exposure 
of the sensitive structures beneath, complicating the quittor 
with a sand-crack of a peculiarly objectionable type. 
Pathological Anatomy of the Diseased Cartilage.— The 
bulk of observers appear to agree in the statement that in 
quittor the necrotic cartilage is pea-green in colour, and 
recognise it by that characteristic. In size the necrotic 
portion thus recognisable varies from the tiniest speck to 
a portion the size of a horse-bean. Commonly, however, 
it is about as large only as a pea. It is seen to be more or 
less detached from the rest of the cartilage, to which it 
is adherent by one of its extremities only. In general 
appearance we can best liken it to the split half of a green 
pea, whilst others have compared it with the green 
sprouting of a seed. The portions of cartilage nearest the 
necrotic piece are also slightly green in colour, thus indi- 
cating that here also the diseased process has commenced. 
This peculiar change of colour in the affected cartilage is 
22—2 
